75-16-07 BRITISH AIRCRAFT CORPORATION: Amendment 39-2278. Applies to Model BAC 1-11, 200 and 400 Series airplanes.
Compliance is required as indicated.
To detect and secure loose ring nuts in the flap primary transmission system, accomplish the following:
(a) Within the next 1,000 hours' time in service after the effective date of this AD, unless already accomplished within the last 1,000 hours' time in service, comply with paragraph (d) of this AD.
(b) Before the accumulation of 1,050 hours' time in service after compliance with paragraph (a), but not before the accumulation of 800 hours' time in service after compliance with that paragraph -
(1) Inspect, by hand, all ring nuts in the flap primary transmission system in the landing gear bays and wings for tightness; and
(2) Inspect for broken ring nut lock wires.
(3) If any ring nut is found to be loose or any ring nut lock wire is found to be broken during the inspections required by subparagraphs (1) and (2) of this paragraph, before further flight comply with paragraph (d).
(c) Before the accumulation of 1,050 hours' time in service after compliance with paragraph (b) of this AD but not before the accumulation of 800 hours' time in service after compliance with that paragraph -
(1) Inspect all ring nuts in the flap primary transmission system in the landing gear bays and wings for a correct torque loading of 35 to 45 pound feet, and inspect for any broken ring nut lock wires; and
(2) Comply with paragraph (d)
(d) Comply with the following as required by paragraphs (a), (b), and (c) of this AD:
(1) Adjust the torque loading of all ring nuts in the flap primary transmission system in the landing gear bays and wings to 35 to 45 pound feet; and
(2) Double wire lock each ring nut using two separate pieces of locking wire.
(e) It is requested that, after complying with paragraphs (b) and (c) of this AD, reports of any loose ring nuts or broken ring nutlock wires found be forwarded to the Chief, Aircraft Certification Staff, AEU-100, FAA, c/o American Embassy, APO New York 09667. Reports should specify the aircraft serial number and location of the ring nuts involved. (Reporting approved by the Bureau of the Budget under BOB No. 04R0174).
(British Aircraft Corporation BAC 1-11 Alert Service Bulletin No. 27-A-PM 5065, dated March 9, 1972, covers this same subject.)
This amendment becomes effective August 27, 1975.